Utilização de biomarcadores enzimáticos e indicadores ecológicos na avaliação de recifes de coral em área marinha protegida

Abstract

Coral reefs are biodiversity rich environments, important to conservation and maintenance of the marine community. Coral reefs also provide goods and services for traditional communities and the local economy. Despite this, the reefs have been suffering from global and local impacts, which cause degradation. This degradation depends on the time of exposure to stressors can lead to changes in the biota from the level of individuals to communities, such as changes in patterns of diversity and abundance, oxidative stress, bleaching and death in corals. This work aimed to test the following hypotheses: 1) reef zones open to human activities, such as tourism and fishing have benthic coverage different from no-take zones; 2) the level of antioxidant enzymes’ activity (related to oxidative stress) is higher in open reef zones than in notake zones and 3) Antioxidant enzymes’ activity differs between healthy and bleached colonies of Siderastrea sp. These hypotheses were tested by estimating the benthic coverage, and collecting 42 stony coral samples: 18 polyps of Mussismilia harttii (Verril 1868) and 24 colonies of Siderastrea sp., aiming to analyze the antioxidant activity of the following enzymes: Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione-S-Transferase (GST), and also levels of Lipid Peroxidation products (LPO), using an integrated biomarker response index (IBR). It was found that the benthic coverage showed differences between zones in terms of composition and abundance of invertebrates/functional groups, and greater similarity between the tourism and the no-take zones. The coralline cover was higher at the tourism zone (9,33%). The M. harttii CAT activity values were highest in the no-take zone. For Siderastrea sp. enzymatic activity values were significantly different only between healthy and bleached specimens, in which bleached individuals had higher GST and LPO enzymatic activity than healthy ones. It is concluded that enzymatic biomarkers showed promising results for bleached corals, indicating cellular damage response, even before the response at the community level.